IODP Expedition 398 Elemental analysis (CHNS)

Fundamental elemental component (total carbon, hydrogen, nitrogen, and sulfur) fluctuations help define the origin, depositional environment, and diagenetic alteration of source materials. To determine C, H, N, and S, solid samples are reacted with a catalyst, separated by chromatography, and detected by thermal conductivity on a FlashEA 1112 CHNS elemental analyzer. Organic carbon can be directly measured on the elemental analyzer by acidification of the sample to drive off carbonate as carbon dioxide before analyzing. Total organic carbon on this report is measured rather than calculated.基础元素组分（总碳、氢、氮与硫）的波动特征，可用于界定物源物质的成因、沉积环境及成岩改造作用。为测定碳、氢、氮、硫元素含量，固体样品需先与催化剂发生反应，经色谱分离后，通过热导检测法在FlashEA 1112型CHNS元素分析仪上完成检测。在分析前，可通过对样品进行酸化处理，使碳酸盐以二氧化碳形式脱除，随后直接在该元素分析仪上测定有机碳（Total Organic Carbon）含量。本报告中的总有机碳均为实测所得，而非通过计算得到。